Gear pump and sump for engine lubrication system



Oct. 9, 1962 G. P. HANLEY 3,057,434

GEAR PUMP AND SUMP FOR ENGINE LUBRICATION SYSTEM Filed March' 24, 1960 '7 Sheets-Sheet l ATTORNEY G. P. HANLEY 3,057,434

GEAR PUMP AND sun/1P EOE ENGINE LUBRICATION SYSTEM Oct. 9, 1962 7 Sheets-Shea?l 2 Filed March 24, 1960 E f@ NR@ Oct. 9, 19.62 G. P. HANLEY 3,057,434

GEAR PUMP AND SUMP FOR ENGINE LUBRICATION SYSTEM 7 sheets-sheet s Filed March 24, 1960 INVENTOR.

ATTORNEY Oct. 9, 1962 3,057,434

GEAR PUMP AND SUMP FOR ENGINE LUBRICATION SYSTEM G. P. HANLEY 7 Sheets-Sheet 4 Filed March 24, 1960 ATTORNEY Oct. 9, 1962 G. P. HANLEY 3,957,434

GEAR PUMP AND SUMP FOR ENGINE LUBRICATION SYSTEM Filed March 24, 1960 7 Sheets-Sheet 5 "www "www IN VEN TOR We? f7/7@ B Y Z ATTORNEY 'I III.

GEAR PUMP AND SUMP FOR ENGINE LUBRICATION SYSTEM Filed March 24, 1960 G. P. HANLEY Oct. 9, 1962 '7 Sheets-Sheet 6 1N VENTQR. n/ye //gy B Y AT Tomvsjy Oct. 9, 1962 G. P. HANLEY 3,057,434

GEAR PUMP AND SUMP FOR ENGINE LUBRICATION SYSTEM Filed March 24, 1960 'T Sheets-Sheet 7 IN VEN T 0R.

United States Patent Ohiice j 3,057,434 Patented Oct. 9, 1962 3,957,434 GEAR PUMP AND SUMP FOR ENGINE LUBRICATIGN SYSTEM George P. Hanley, Northville, Mich., assigner to General Motors Corporation, Detroit, Mich., a corporation of Delaware Filed Mar. 24, 1960. Ser. No. 17,287 17 Claims. (Cl. 184-6) This invention relates tolubricating systems for internal combustion engines; more particularly to a gear pump mechanism and associated sump structure cooperating with the lubricating system of the basic engine to provide a multiplicity of interchangeable and alternative pump drive and sump arrangements to accommodate various engine installation requirements as to accessory mounting location and crankcase oil sump clearances; and with regard to certain more specific aspects thereof to a combined scavenging and pressure supply gear-type pump mechanism and sump structure cooperating therewith.

In the past, various installation requirements for a given internal combustion engine in different applications have necessitated the provision for and use of alternative components relating to the pump mounting, drive arrangement, the fluid connections thereto and the associated sump constructions. The arrangement of such alternative components has often been necessarily complex and difficult to assemble and service. The limited production generally involved in such alternative constructions has also increased unit component costs and increased the diiculty and cost in assembling the engine on a production line basis. The inventory and space required for storage of the numerous parts required for production and service has further increased the cost per engine or service unit.

The invention contemplates a gear pump having a drive and mounting arrangement accommodating either hand of crankshaft rotation independent of the uid connections thereto; a gear pump having an internal passage arrangement increasing the installation versatility thereof and minimizing the number and complexity of external fluid connections or conduits required to meet various installation requirements; and a gear pump having an inlet and discharge port construction increasing the pumping displacement and hence volumetric efficiency of the pump unit. With regard to certain of its more specific aspects, the invention contemplates a basic gear pump which is particularly adapted to serve as a lubricant pressure supply pump for an internal combustion engine and a sump structure associated therewith adapted to accommodate various engine installation requirements, and which is readily convertible to a combined scavenging and lubrication pressure supply pump with a minimum of additional or substitute pump components. With reference to certain other more specific aspects, the invention contemplates a gear pump which is particularly adapted to serve as a lubricant pressure supply pump for an internal combustion engine such as shown and described in copending United States patent application S.N. 1,488 led January ll, 1960, in the names of Harold H. Albinson, George P. Hanley, Kenneth L. Hulsing, Harvey G. Humphries and John I. May entitled Two Cycle Internal Combustion Engine. In such an installation, the invention contemplates a gear pump mounted to have the rotative impeller axes thereof in equispaced parallel relation to the crankshaft rotative axis and disposed symmetrically with respect to the vertical median plane of the engine including the crankshaft rotative axis; having impeller shafts parallel to and in a plane tangent to the rotative axis of the crankshaft and spaced equally on each side of the radius to the point of plane Vtangency; having inlet ports connectable alternatively to the sumps adjacent to or intermediate the ends of the engine; and having a discharge chamber which is alternatively connectable at laterally opposite sides thereof to an inlet port opening to and communicating with an oil distribution passage formed in and extending transversely of the crankcase or frame.

The foregoing and other objects, advantages and features of the invention will become apparent from the following description of the preferred illustrative embodiment of the invention, reference being made therein to the several drawings, in which:

FIGURE 1 is a transverse sectional view through the lower portion of an internal combustion engine and shows a combined scavenge and pressure supply gear pu-mp as constructed and mounted in accordance with the invention, the fluid connections thereto, the associated oil distribution passages of the engine and the crankcase oil pan sump structure of the invention partially in section and in front elevation;

FIGURE 2 is a view taken substantially in the direction of the arrows and in the plane of the line indicated at 2 2 in FIGURE l and shows the sump defining oil pan structure of the invention in longitudinal section and the oil pump of the invention and fluid connections thereto in side elevation;

FIGURE 3 is a view taken substantially in the direction of the arrows and in the plane of the line indicated at 3-3 in FIGURE 2;

FIGURE 4 is a View similar to FIGURE 2 showing a modified oil pan sump arrangement and fluid connections accommodating mounting and drive of the combined scavenging and lubricant pressure pump adjacent the rear of the engine;

FIGURE 5 is a view similar to FIGURE 3 showing the pump and uid connections of FIGURE 4 in top elevation and is taken substantially in the direction of the arrows and in the plane of the line indicated at 5-5 in FIGURE 4;

FIGURE 6 is a sectional view of the combined pump taken substantially in the direction of the arrows and the plane of the line indicated at 6--6 in FIGURE 2 with additional portions thereof broken away and in section to show certain additional details of the pump construction;

FIGURE 7 is a sectional view of the pump taken su-bstantially in the direction of the arrows and in the plane of the line 7-7 indicated in FIGURE 6;

FIGURES 8, 9, 10 and l1 are transverse sectional views of the combined pump assembly and are taken substantially in the direction of the arrows and in the succeeding parallel planes indicated by corresponding numerals in FIGURE 6;

FIGURE l2 is an exploded perspective view showing the pump of the invention as modified to act solely as a lubricant pressure supply pump in certain engine installations; and

FIGURE 13 is a view showing the porting detail of a pump housing member adapting the combined pump of the invention to the single pump construction of FIG- URE 12.

Referring more particularly to FIGURE 1, an internal combustion engine is partially indicated at 10 and comprises a cylinder block or engine frame member 11 having a lower crankcase portion 12. A plurality of spaced parallel webs extend transversely between crankcase side walls 13 and 13 and define bearing supporting arches 14. A crankshaft 15 having a plurality of spaced journal portions 16 is rotatably supported by a plurality of bearings 17 carried by the arches 14 and by mating bearing caps 14 secured thereto. An oil pan assembly 18 is secured to the bottom coplanar faces rof the crankcase side walls by a plurality of bolts indicated at 19. The oil pan assembly 18 serves as a bottom closure for the crankcase chamber and in the illustrative embodiments of FIG- URES 1-5 defines both a dry scavenge sump and a. wet main oil sump.

Two passages 20 and 21 extend vertically of the crankcase side walls immediately adjacent to the front end thereof and intersect the two coplanar lbottom faces 22 and 23 thereof to define ports 24 and 25, respectively. The vertical passage 20 is divided by a plug 26 into a lower portion 27 and an upper portion 28. At their upper ends, the vertical passages 20 and 21 are intersected by passages 29 and 30, respectively, which extend obliquely and upwardly therefrom to a main distribution gallery 32. The gallery 32 extends longitudinally from the intersection of the passages 29 and 30 in the median vertical plane of the cylinder block. The port 24 of the lower passage 27 is connected `by an elbow fitting 34 to the pressure discharge port of a combined scavenge and oil pressure supply gear pump indicated generally by the reference numeral 36. The pump 36 is constructed and mounted in accordance with the invention as described in greater detail below.

From the passage portion 27, the pump supplied pressurized lubricant passes through a port 27 in the crankcase side wall 13 and into an inlet chamber 38 of a combined oil filter and cooler unit indicated generally by the reference numeral 40. A pressure regulating valve mechanism 44 is housed in the elbow fitting 34 and serves to limit the pump supplied pressure delivered to the filtercooler unit below a predetermined maximum level. After passing through the filter and cooler unit, the lubricant is returned through the outlet chamber 42 of the unit and a mating port 28' in the crankcase side wall to the upper passage portion 2S and the remainder of the cylinder block oil distribution system. A pressure regulating valve 46 closes the lower port 25 of the vertical passage 21 and serves to control the distribution gallery pressure at a desired pressure level less than that supplied by the pump and the pressure regulating valve 44 to the filter and cooler unit.

The several passages 20, 29, 30 and 21 define an oil distribution manifold or gallery of arched configuration transversely of the engine crankcase and have substantial symmetry with respect to the vertical median plane of the engine. To accommodate various engine installation requirements, an alternative location for the oil filter and cooler unit is provided on the side of the engine opposite that shown. For this purpose, the vertical passage 21 may be intersected by spaced parallel ports 27 and 28" as shown. These ports are coaxial with the ports intersecting the passage 20 and sealed -by a suitable closure plate as indicated at 48. The side face of the crankcase wall to which the closure plate 48 is secured is machined to provide the alternative oil filter and cooler mounting location. For such alternative mounting of the oil filter and cooler unit, the closure plate 48 is installed to seal the ports 27 and 28. The gallery pressure regulating valve 46 and the pump discharge regulating valve and elbow 34 are also interchanged with respect to the ports 24 and 25 and the plug 26 is installed at 26' in the passage 21 leaving the vertical passage 20 unrestricted intermediate its ends.

The oil pan assembly 18 shown in FIGURES 1 and 2 comprises a main pan member 50 having side walls indicated at 51, 52, 53 and 54. A bottom wall 55 extends transversely between the side walls 53 and 54 and longitudinally between two openings 56 and 57 formed adjacent the ends of the main pan member. A boss 58 adjacent the lower ends of the pan side walls reinforces the juncture of the bottom and side walls and partially defines the openings 56 and 57. Two ribs or bosses 59 and 60 extend transversely of the bottom wall between the longitudinally extending side portions of the boss l58 and define the remainder of the openings 56 and 57. Several additional reinforcing bosses or ribs 61 extend transversely of the bottom wall in spaced parallel relation to each other and to the bosses 59 and 6i).

The opening 56 is closed by a cover member 62 which is sealingly secured to the opening `bosses 58 and 59, as by a plurality of bolts indicated at 63. The cover member 62 and the opening bosses 58 and 59 dene a relatively shallow sump 64. In the embodiment of FIGURES l and 2, the sump 64 serves as a dry scavenge sump. Where the engine normally operates in a near horizontal position, the opening 57 may be similarly closed by a sump defining covermen'iber identical to and interchangeable with the cover member f62. In such an installation, the suction intake or intakes of a simple oil pressure supply pump, as shown in FIGURE l0, may be connected to either or both of the shallow cover defined sumps. Where a substantial amount of engine gradability is required in motor vehicles and marine applications, however, a secondary pan member 65 closes the second opening 57 of the main pan member, being secured by bolts 66 to the boss 58 and the rib `61 distal from the opening 57. The pan member 65 thus serves to define a main oil sump 67. The bottom wall 55 of the main pan member forms a baffle insuring a sufficient intake immersing Oil level under all expected lateral roll and longitudinal pitch conditions. Referring to the oil pan arrangement of FIGURE 4, it will be seen that the cover member 62 and the secondary oil pan member 65 may be interchanged to meet different installation requirements as to oil pan clearance. The oil pan assembly of the invention thus meets a multiplicity of installation clearance and sump requirements.

The pump 36 includes both an oil pressure supply pump 70 and a companion scavenging pump 72. These individual pumps are of gear type and arranged to be driven in tandem. As shown in FIGURES 2 and 3 and in FIG- URES 4 and 5, respectively, the combined oil pressure and scavenging pump 36 may be mounted in the crankcase oil pan compartment adjacent either the front or rear of the engine. In either location, the pump is gear driven from the engine crankshaft and has appropriate fluid connections accommodating the associated oil pan sump arrangement. The oil pressure pump may also be modified for independent use as indicated above and described in greater detail below with reference to FIG- URES l2 and 13.

The details of the combined oil pressure and scavenging pump 36 are best shown in FIGURES 6-ll. The combined pump comprises an oil pump body member 74 and a scavenge pump body member 76. The adjacent ends of the body members 74 and 76 are recessed and cooperate with a partition seal plate 78 sandwiched therebetween to define an oil pump chamber 80 and a scavenge pump chamber 82, respectively. The several body members are secured together by a plurality of bolts 34 which extend through the scavenge pump body member and the partition plate and threadably engage tapped holes in the oil pump body member 74 as shown. The combined pump assembly is supported by two longitudinally spaced flanged bosses 86 and 88 which extend transversely of the oil pump ybody member and are secured by suitable bolts 90 to the undersides of two of the crankshaft bearing caps 14 adjacent either the front or the rear on the engine block.

An oil inlet portis formed in the left side face of theoil pump body member at 91 and is connected to the main sump 67 `through an intake filter screen assembly 92 and an inlet tube -assembly 93. Inwardly of the pump body member 74, the port 91 communicates with an `oil inlet chamber 94 which extends transversely of and is coextensive with the lower suction side of the pump chamber Si). A pressure discharge chamber 96 opens on and is coextensive with the upper pressure discharge side of the pump chamber 80. Two alternative pressure outlet ports formed at 100- and 102 in the opposite side walls of the body member are connected to the pressure discharge chamber 96 through an outlet compartment or passage 98 formed forwardly of the pump chamber 80.

In the several illustrative embodiments, the outlet port 100 of the oil pump is connected to the oil inlet port 24 of the cylinder block either through the elbow fitting 34 with the front mounted pump of FIGURES l-3 or through a tube assembly with the rear mounted pump of FIGURES 4 and 5. To accommodate mounting of the oil filter-cooler unit et) on the opposite crankcase side wall 13 adjacent the front of the engine, the alternate block inlet port 25 is connectable either to the outlet port 102 of the front mounted pump through a pressure regulating valve and elbow fitting similar to 34 or to the port of the rear mounted pump through an alternate tube assembly similar to 35. The pump outlet port opposite the fitting 34 may be cast closed for original engine manufacture but is preferably closed by a closure plate 103 as shown. By providing a symmetrical transversely extending oil distribution manifold or gallery adjacent the rear of the engine :block corresponding to the previously described passage 20, 29, 30` and 21, as in the aforementioned application S.N. 1,488, alternate mounting locations for the oil filter-cooler unit may also be provided adjacent the rear of the engine with appropriate fluid connections accommodating the mounting of the pump unit adjacent either the front or rear of the engine.

A scavenge pump inlet port is provided at 104 in the bottom wall of the oil pump body member just forwardly of the oil inlet chamber 94. In either embodiment, the port 104 is connected to the adjacent scavenge sump 64 of the oil pan assembly 18 through an intake filter screen assemb-ly 105. A passage 106 in the oil pump body member extends transversely and rearwardly from the port 164 to a port 108 opening on the face of the oil pump body mating wit-h the partition plate 7 8. The partition plate 78 is provided with a port 112 which is alignable with and connects the port 108 with a port 114 opening on the plate mating face of the scavenge pump body member 76. A passage 116 extends rearwardly from the port 114 and then transversely across the lower rear of the pump body member 78. The transverse portion of the passage 116 merges with a scavenge pump inlet chamber 118 which extends forwardly therefrom and is coextensive with the lower suction side of the scavenge pump chamber 82. A pressure discharge chamber 120 is formed in the upper portion of the scavenge pump body member and opens on and is coextensive with the upper pressure discharge side of the pump chamber 82. The outlet chamber 120 is connected by a downwardly and transversely extending passage 122 to a port opening at 124 through the rear wall of the scavenge pump body member. A discharge tube 125 is connected at one end to the outlet port 124, being secured to and supported by the rear face of the scavenge pump body member 76. At its opposite end, the tube 125 discharges the scavenged oil into the main oil sump 67.

The front wall 126 of the oil pump body member 74, and the partition wall 128 thereof separating the pumping chamber 80 from the pressure discharge compartment 98 and the pump chamber defining Wall 130 of the scavenging pump body member 76 have upstanding paralleled bosses 126 and 126", 128 and 128", and 130 and 130, respectively, which are formed integrally therewith and define spaced parallel bores 132 and 132, 134 and 134", and 136 'and 136, respectively. The partition plate 78 is similarly provided with two parallel spaced bores 138' and 138". In assembly, the several bores 132', 134', 136 and 138 are in axial alignment with each other and the bores 132", 134", 136l and 138 are similarly aligned. Plain bearings 140 are suitably mounted in each of the several aligned bores of the body members 74 and 76 and journal two identical and interchangeable impeller shafts 142 and 142". These shafts are spaceably embraced by the bores 138 and 138 through the partition plate 78.

Two identical impeller gears 144 and 146 are keyed to the shafts 142 and 142 within the oil pumping chamber 80. The teeth of the gears 144 and 146 drivingly and sealingly enmesh and define a plurality of pumping cornpartments in cooperation with limited arcuate sealing surfaces 148 and 150 which partially define the side walls of the pumping chamber 80. For quietness, the gear teeth are preferably formed with a slight helix angle thus providing herringbone engagement. For simplicity of illustration, however, these teeth are shown as being straight. The shafts 142' and 142" similarly mount a second set of gears 152 and 154 within the pumping compartment 82 of the scavenge pump. The gears 152 and 154 are identical to and interchangeable with the gears 144 and 146. The teeth of the gears 152 and 154 also drivingly and sealingly enmesh `and define a plurality of pumping compartments by rotation of the outer lands thereof in sealing relation with limited arcuate surfaces 156 and 158 partially defining the side walls of the pumping chamber 82. The driven gears 146 and 154 of the illustrative pump embodiment are preferably keyed to their respective mounting shafts as shown to permit interchangeable use of the pump unit in either its front or rear mounting location and with either hand of crankshaft rotation.

The ends of the impeller shafts 142 and 14'2" distal from the scavenge pump project forwardly of the oil pump front wall 126. In `accordance with certain aspects of the invention, the rotative axes of these shafts are parallel to and in a common plane tangent to a cylindrical arc about the rotative axis of the crankshaft and are spaced equally on each side of a radius to the point of plane tangency; in other words, the shaft axes are equi-spaced and parallel to the crankshaft axis and disposed symmetrically with respect to the vertical median plane of the engine including the rotative axis of the crankshaft. Depending upon the direction of crankshaft rotation, a gear is drivingly keyed to one of the projecting ends of the shafts 142 or 142". The gear 160 is in turn engaged lby a gear drivingly carried by the engine crankshaft 15. This crankshaft gear is indicated at 162 lin FIGURE 1. Asbest seen in FIGURE 6, the shaft embracing hub 16fla of the gear 160 extends longitudinally from the gear spider 160b and thus permits the spider to clear the end of the other .impeller shaft. rlhis gear structure thus cooperates with the indicated shaft geometry and the keying of several impeller gears on identical shafts to permit the interchangeable use of the pump unit of the invention in either a front or rear mounted location with either hand of crankshaft rotation. Assuming counterclockwise rotation of the engine crankshaft 15 as viewed in FIGURE l, the pump driving gear 160 is necessarily keyed to the outwardly projecting end of the shaft 142 as shown in the several illustrative embodiments. The resultant impeller rotation provides pumping displacement of fluid between the inlet chambers 94 and 118 and the discharge chambers 96 and 120 of the oil pressure and scavenge pump, respectively.

Because of the several indicated features contributing lto the interchangeability of the mounting and drive of the pump unit 36, the several impeller gears and the overall pump unit 36 are necessarily of substantial axial dimension to provide the required pumping displacement while minimizing the transverse and vertical dimensions of the pump unit and of the adjacent oil pan structure. Since the pumped fluid is positively .displaced from the several gear teeth compartments on the pump discharge side, the volumetric pumping efficiency is ldependent upon the filling characteristic of the several tooth defined compartments on the inlet chamber side of the individual pump unit and upon the rotative seal provided by the gear teeth between the inlet and discharge chambers. The inlet ll characteristics have been found to be a function of the centrifugal forces acting 4on the fluid, the viscosity of the pumped fluid and of the time of inlet chamber exposure permitted for compartment fill. In the instant oil and scavenge pump units, the gear tooth fill exposure provided by the dimensions of the inlet chambers 94 and 118 tends lto insure adequate fill of the necessarily long gear tooth pumping compartments provided by the impeller gears. To further insure adequate compartment fill and further increase the volumetric efficiency over the entire engine speed range, the side Walls 164 and 166 defining the oil pump chamber 80 are arcuately relieved at 168 and 170 as best seen at FIGURE 9 and the side walls 172 and 174 defining the scavenge pump cham-ber 82 are similarly relieved at 176 and 178 as best seen in FIGURE l1. Such relieving provides clearance with the outer gear teeth lands and thus defines arcuate fill insuring extensions of the inlet chambers 94 and 118.

Referring now more particularly to the separate oil pump embodiment of FIGURES 12 and 13, only an oil pump is necessary to insure proper engine lubrication in installations Where the engine operating disposition remains substantially level. In such an installation the oil pressure pump 7i) defined principally by the housing member 74 is used with a cover member 180 cooperating therewith to define the end wall of the pumping chamber. The cover member 180 is cored 4to provide a passage 182 which extends transversely thereof and has ports 184 and 186 mating respectively with the port 108 and the inlet chamber 94 of the pump body member 74. A third port 18S extends through the rear wall of the cover member and intersects the passage 182. The cover member 180 thus provides three alternative inlet ports defined by the ports 91 and 104 in the oil pump body member and by the port 188 of the cover member. The ports 91 and 104 are, of course, connectable to the previously described sumps 67 or 64, respectively, by the intake filter-screen and tube assembly 92, 93 or by the filter-screen intake assembly 105. As shown in FIGURE 12, the port 188 is connectable to either a shallow or deep sump adjacent the rear of the engine by a filter intake screen and tube Vassembly 190. In this separate oil pump embodiment, the oil pump impeller gears 144 and 146 are drivingly keyed to relatively short shafts 194 and 194", one of which is gear-driven off the crankshaft in the manner previously described. These shafts are journalled by the spaced bushings 140 carried by the body member Walls 126 and 128. The shafts 194 and y194 may also be journalled adjacent their rear ends as shown by bearings 196 carried by the cover member 180 in alignment with the bearings 140 of the pump body member. The bearings 196 are, of course, identical to and interchangeable with the bearings 140.

From the foregoing description, it will be seen that the combined oil and scavenging pump embodiment of FIG- URES 1-11 and the sep-arate oil pump embodiment of FIGURES l2 and 13 provide maximum mounting and drive versatility and are adapted to accommodate a plurality of oil pan sump arrangements using a minimum number of interchangeable parts and with relatively simple tubing and fittings externally of the pump proper. This is in marked contrast to previously known engine lubricating pumps of this type wherein the various inlet and outlet pipes and fittings are relatively complex, wherein an idler gear drive is necessary to accommodate different hands of crankshaft rotation or the pump is necessarily designed to accommodate a single specific oil pan sump and drive arrangement with a single oil connection to the block of the engine. It will be seen further that the invention provides an improved port arrangement increasing volumetric efficiency and providing a pump of minimum transverse dimensions thereby reducing oil pan clearance requirements.

While the description of the invention has been limited to several illustrative embodiments, it will be appreciated that various modifications and changes might be made therein without departing from the spirit and scope thereof, as defined in the following claims.

I claim:

1. In an internal combustion engine having a cylinder 8 block cooperating with an oil pan to define a crankcase oil sump chamber and having oil distribution passages therein terminating in a port opening on the crankcase chamber, said engine having a crankshaft rotatably supported in said crankcase chamber by a plurality of spaced bearing means carried yby the cylinder block: a gear pump mounted within said crankcase chamber and including a housing carried by said bearing means, said pump housing defining an impeller gear mounting pump chamber extending longitudinally thereof in spaced parallel relation to the crankshaft rotative axis, an inlet chamber extending longitudinally of and opening on the lower portion of the pumping chamber and a discharge chamber extetnding longitudinally of and opening on the upper portion of the pumping chamber, a first passage means connecting said inlet chamber to the oil sump, and a second passage means connecting said discharge chamber to said port of the -block defined oil distribution passages, said pump including two impeller shafts extending through said pumping chamber and journaled by said housing in parallel spaced symmetrical relation to a common tangent plane passing therebetween and through the crankshaft rotative axis, two impeller gears drivingly secured to said impeller shafts within said pumping chamber and having fluid pumping interengagement with each other and rotative sealing clearances with the housing surfaces defining said pumping chamber, said impeller shafts being interchangeable and projecting equally at one end thereof from said pump housing, a pump driving gear member secured to said crankshaft and a driven gear secured to one of said impeller shaft ends and drivingly engaged by said driving gear member to effect pumping displacement of fluid between said inlet and discharge chambers upon a given hand of crankshaft rotation, said second gear including a spider portion having axially spaced clearance with the other impeller shaft and being mountable on said other impeller shaft to effect pumping displacement between said inlet and discharge chambers upon rotation of the crankshaft in the opposite direction.

2. In an internal combustion engine having a cylinder block cooperating with an oil pan to define a crankcase oil sump chamber and having oil distribution passages therein, said engine having a crankshaft rotatably supported in said crankcase chamber by a plurality of spaced bearing means carried by the cylinder block: a gear pump mounted within said crankcase chamber and including a housing carried by said bearing means, said pump housing defining a pumping chamber, two impeller shafts extending through said pumping chamber and journaled by said housing in equidistant parallel relation to the crankshaft rotative axis and a common tangent plane passing therebetween and through the crankshaft rotative axis, two impeller gears drivingly secured to said impeller shafts within said pumping chamber and having fiuid pumping interengagement with each other and rotative Sealing clearances with the housing surfaces defining said pumping chamber, said impeller gears and shafts being interchangeable and said shafts projecting equally from said pump housing at one end thereof, said housing having an inlet chamber opening on the lower portion of the pumping chamber and a discharge chamber opening on the upper portion of the pumping chamber, a first passage means connecting said inlet chamber to the oil sump, and a second passage means connecting said discharge chamber to the block defined oil distribution passages, a pump driving gear member secured to said crankshaft and a driven gear member secured to one of said impeller shaft ends and drivingly engaged by said crankshaft gear member to effect pumping displacement of fiuid between said inlet and discharge chambers upon a given hand of crankshaft rotation, said driven gear including a( spider portion having axial clearance with the other impeller shaft and being mountable on said other impeller shaft to effect pumping displacement between said inlet and discharge chambers upon rotation of the crankshaft in the opposite direction.

3. 4In an internal combustion engine having a cylinder block cooperating with an oil pan to define a crankcase oil sump chamber, said block having an oil distribution passage extending transversely adjacent one end thereof and terminating in ports opening to the sump chamber, said engine having a crankshaft rotatably supported by spaced bearing means carried by said cylinder block: a gear pump mounted within said sump chamber adjacent said one end, said pump having an inlet chamber connected to the oil sump and a laterally extending discharge chamber connected to one of said block defined passage ports, said pump including two impeller shafts projecting equally from said pump and journaled -in spaced parallel relation equidistant and symmetrical to a common tangent plane passing therebetween and through the crankshaft rotative axis, a first gear member drivingly secured to said crankshaft, and a second gear member secured to one of said shaft ends and drivingly engaged by said first gear member to effect pump displacement of fluid between said inlet and discharge chambers upon a given hand of crankshaft rotation, said second gear having a spider portion having axially spaced clearance with the other of said shaft ends and being mountable on the other of said shaft ends to effect pump displacement between said inlet and discharge chambers upon rotation of said crankshaft in the opposite direction.

4. In an internal combustion engine, a cylinder block having oil distribution passages therein, an oil pan secured to and defining a crankcase and oil sump chamber with said block, spaced bearing means carried by said block and rotatably supporting a crankshaft within said crankcase chamber, a gear pump mounted within said crankcase chamber, said pump having fluid connections with the oil sump and said block defined passages, said pump including two impeller shafts journaled in spaced parallel relation equidistant from and symmetrically disposed with respect to a plane including the rotative axis of t-he crankshaft, a first gear member secured to said crankshaft, and a second gear member secured to `one of said impeller shafts and drivingly engaged by said first gear member to effect pumping displacement of oil lthrough said pump to the oil distribution passages of said block upon a given hand of crankshaft rotation, said second gear having a spider portion having clearance with the other of said shafts and being mountable on the other of said shaft ends to effect pumping displacement with rotation of said crankshaft in the opposite direction.

5. In an internal combustion engine, a cylinder block having oil distribution passages therein, an oil pan secured to said block to define `a crankcase and oil sump chamber, spaced bearing means carried by said block and rotatably supporting a crankshaft within said crankcase chamber, means supporting a gear pump within said crankcase chamber, said pump having an inlet chamber connected to the oil sump and a discharge chamber connected to one `of said block defined passages and said pump including two impeller gears journaled in spaced parallel relation and equidistant from and symmetrical to a common tangent plane passing therebetween and including the rotative axis of the cranks-haft, a driving gear member secured to said crankshaft, and a driven gear member drivingly connected to one of said impeller gears and engaged by said first gear member to effect pumping displacement of fluid between said inlet and discharge chambers upon a given hand of crankshaft rotation, and said driven gear being drivingly connectable to the other of said impellers to effect fluid pumping displacement between said inlet and discharge chambers for an opposite hand of crankshaft rotation.

6. In an internal combustion engine, a cylinder block having oil distribution passages therein, an oil pan secured to and defining a crankcase and oil sump chamber with said block, said oil pan defining a relatively shallow scavenge sump adjacent one end thereof and a main sump adjacent the opposite end thereof, spaced bearing means carried by said block and rotatably supporting a crankshaft Within said crankcase chamber, a compound gear pump mechanism mounted within said crankcase chamber adjacent said one end and including a first housing member secured to and carried by said bearing means adjacent said one end, said first housing member defining a first pumping chamber extending longitudinally thereof in spaced parallel relation to Ithe rotative axis of said crankshaft, -an inlet chamber extending longitudinally of and opening to the lower portion of said first pumping chamber, a discharge chamber opening on the upper portion of said first pumping chamber and extending longitudinally therefrom lto a portion extending laterally of said housing and first pumping chamber, and an inlet passage extending longitudinally of said housing adjacent one side of the first pumping chamber from an inlet port in the bottom wall of said housing forwardly of said pumping chamber to a port opening in an end face thereof, a partition plate having a port therein mating with said first housing end face and port and closing said first pumping chamber, a second housing member secured to said first housing member and partition plate and defining a second pumping chamber extending longitudinally thereof in alignment with said first pumping chamber, a second inlet chamber extending longitudinally of and opening to the lower portion of said second pumping chamber, an inlet passage extending longitudinally of said second housing adjacent said second pumping chamber and interconnecting said second inlet chamber with the inlet passage of said first housing member, and a second discharge chamber opening on the upper portion of said -second pumping chamber and extending longitudinally therefrom to a portion extending laterally of said second housing member and pumping chamber in the end thereof opposite said first housing member, two impeller shafts journaled by said housing members and extending through said pumping chambers in parallel spaced symmetrical relation to a common tangent plane passing therebetween and through the crankshaft rotative axis, an -impeller gear drivingly secured to each impeller shaft within each of said pumping chambers and having fluid pumping interengagement with each other and rotative sealing ,clearances with the housing and partition plate surfaces defining their respective pumping chambers, said impeller gears and shafts being interchangeable and said shafts projecting equally from one of said pump housing members, a gear member drivingly secured to said crankshaft and a driven gear secured to one of said impeller shaft ends and drivingly engaged by said crankshaft gear member to effect pumping displacement of fluid between the inlet and discharge chambers upon a given hand of crankshaft rotation, said driven gear including a spider portion having axial clearance with the other impeller shaft and being mountable on said other impeller shaft to effect pumping displacement between said inlet and discharge chambers upon rotation of the crankshaft in the opposite direction, intake means connecting said inlet port to the adjacent scavenge sump, a conduit having one end connected to the discharge chamber of said second housing and adapted to discharge pumped fluid from its distal end into the main sump, a second intake means located in said main sump and having fluid connection with the intake cham-ber of said first housing member, and a fluid connection between the discharge chamber of said first housing member and the oil distribution passages of said cylinder block.

7. VIn an internal combustion engine, .a ,cylinder block having oil distribution passages therein, Ian oil pan secured to and defining a crankcase and oil sump chamber with said block, said oil pan defining a relatively shallow scavenge sump adjacent one end thereof and a main sump adjacent the opposite end thereof, spaced bearing means carried by said block and rotatably supporting a crankshaft within said crankcase chamber, a gear pump mechanism mounted within said crankcase chamber and including first and second housing members secured together and carried by certain of said bearing means, said first housing member defining a first pumping chamber extending longitudinally thereof in spaced parallel relation to the rotative axis of said crankshaft, an inlet chamber extending longitudinally of and opening to the lower portion of said first pumping chamber and a discharge chamber opening on the upper portion of said first pumping chamber and extending longitudinally therefrom to a chamber portion extending laterally of the end of said first housing chamber opposite said second housing member, said second housing member defining a second pumping chamber extending longitudinally thereof in alignment with said first pumping chamber, a second inlet chamber extending longitudinally of and opening to the lower portion of said second pumping chamber and a second discharge chamber opening on the upper portion of said second pumping chamber and extending longitudinally therefrom to a chamber portion extending laterally of said second housing member in the end thereof opposite said first housing member, intake means located in said scavenge sump and having fluid connection with said second inlet chamber, a conduit connected at one end to the discharge chamber of said second housing and adapted to discharge pumped fluid from its distal end into the main sump, a second intake means located in said main sump and having fluid connection with the inlet chamber of said first housing member, a fluid connection between the discharge chamber of said first housing member and the oil distribution passages of said cylinder block, two impeller shafts journaled by said housing members and extending through said pumping chambers in parallel spaced symmetrical relation to a common tangent plane passing therebetween and through the crankshaft rotative axis, an impeller gear drivingly secured to each impeller shaft within each of said pumping chambers and having fluid pumping interengagement with each other and rotative sealing clearances with the housing surfaces defining their respective pumping chambers, said impeller gears and shafts being interchangeable and said shafts projecting equally from one of said pump housing members, `a gear member drivingly secured to said crankshaft, and a driven gear secured to the projecting end of one of said impeller shafts and drivingly engaged by said crankshaft gear to effect pumping displacement between said inlet and discharge chambers, said last mentioned gear including a spider portion having axial clearance with the other impeller shaft and being alternatively mountable on either of said impeller shafts thereby accommodating either hand of crankshaft rotation.

8. In an internal combustion engine having a cylinder block with oil distribution passages therein, an oil pan secured to and defining a crankcase and oil sump chamber with said block, said oil pan defining a relatively shallow scavenge sump and a main sump adjacent opposite ends thereof, and spaced bearing means carried by said block and rotatably supporting a crankshaft within said crankcase chamber: a combined gear pump mechanism mounted within said crankcase chamber and including first and second housing members secured together and carried by certain of said bearing means, said housing members defining longitudinally aligned first and second pumping chambers extending in parallel relation to the rotative axis of said crankshaft, first and second inlet chambers extending longitudinally of and opening to the lower portions of said first and second pumping chambers and first and second discharge chambers extending longitudinally of and opening on the upper portion of said first and second pumping chambers, intake means located in the scavenge sump and having iiuidV connection with one of said inlet chambers, a conduit connected to the discharge chamber opposite said one inlet chamber and adapted to discharge pumped fluid into the main sump, a second intake means located in the main sump and having fiuid connection with the other of said inlet chambers, a fluid connection between the discharge chamber opposite said other inlet chamber and the oil distribution passages of said cylinder block, two impeller shafts journaled by said housing members and extending through said pumping chambers in symmetrical parallel relation to a cornmon tangent plane passing therebetween and through the crankshaft rotative axis, an impeller gear drivingly secured to each impeller shaft within each of said pumping chambers and having fluid pumping interengagement with each other and rotative sealing clearances with the housing surfaces defining their respective pumping chambers, said shafts projecting equally from one of said housing members, a gear member drivingly secured to said crankshaft, and a driven gear secured to the projecting end of one of said impeller shafts and drivingly engaged by said crankshaft gear member to effect pumping displacement of iiuid between the inlet and discharge chambers, said last mentioned gear including a spider portion having axial clearance with the other impeller shaft and being alternatively moun-table on either of said impeller shafts thereby accommodating either hand of crankshaft rotation.

9. In an internal combustion engine, a cylinder block having oil distribution passages therein, an oil pan secured to and defining a crankcase and oil sump chamber with said block, said oil pan defining a relatively shallow scavenge sump and a main sump, spaced bearing means carried by said block and rotatably supporting a crankshaft within said crankcase chamber, a combined gear pump mechanism mounted Within said crankcase chamber and including a housing defining first and second pumping chambers extending in parallel tandem relation to the crankshaft rotative axis, said housing having inlet chambers opening to the lower portions of said pumping chambers and discharge chambers opening on the upper portions of said pumping chambers, a first intake means in said scavenge sump having uid connection with one of said inlet chambers, a conduit connected to the discharge chamber opposite said one inlet chamber and adapted to discharge pumped fiuid into the main sump, a second intake means in said main sump having fluid connection with the other of said inlet chambers, a fluid connection between the discharge chamber opposite said other inlet chamber and the oil distribution passages of said cylinder block, two impeller shafts journaled in and projecting from said housing in symmetrical parallel relation to the crankshaft rotative axis and a common tangent plane passing therebetween and through the crankshaft rotative axis, an impeller gear secured to each impeller shaft within each pumping chamber, the impeller gears in each pumping chamber having fluid pumping interengagement with each other and rotative sealing clearance with the housing surfaces defining their respective pumping chambers, a gear member drivingly secured t0 said crankshaft and a driven gear secured to the projecting end of one of said impeller shafts and drivingly engaged by said crankshaft gear member to effect pumping displacement of fiuid between the inlet and discharge chambers, said last mentioned gear including a spider portion having axial clearance with the other impeller shaft and being mountable on either of said impeller shafts to accommodate crankshaft rotation in either direction.

l0. In the combination set forth in claim 9, said pumping chambers and impeller gears being of longitudinal dimension exceeding the pitch diameters of the several impeller gears and the pumping chamber defining portions of said housing having a first plurality of arcuate surfaces of limited sector in rotative sealing clearance with the peripheries of the impeller gears adjacent the discharge chambers and a second plurality of arcuate surfaces intersecting said first arcuate surfaces and defining spaced rotative clearances with the periphery of said impeller 13 gears adjacent said inlet chambers thereby providing arcuate extensions of said inlet chambers.

1l. In the combination set forth in claim 9, said pumping chambers and impeller gears being of substantial longitudinal dimension relative to the pitch diameters of the several impeller gears and the pumping chamber defining portions of said housing having a first plurality of arcuate surfaces defining spaced rotative clearances with the periphery of said impeller gears adjacent said inlet chambers thereby providing arcuate extensions of said inlet chambers, a second plurality of arcuate surfaces of limited sector intersecting said first arcuate surfaces and in rotative sealing clearances with the peripheries of said impeller gears between said first arcuate surfaces and said discharge chambers.

l2. In an internal combustion engine as set forth in claim 9, said oil pan including a first pan member comprising side and end walls and a bottom wall extending between said side walls and cooperating with said side and end walls to define openings of like peripheral configuration adjacent each end of said first pan member, a second pan member secured to said first pan member and closing one of said openings and cooperating with said first pan member to define said main sump, and a third pan member secured to and closing the other of said openings and cooperating with said first pan member to define said scavenge sump.

13. In an internal combustion engine as set forth in claim 9, said oil pan including a primary pan member comprising side and end walls and a bottom wall extending between said side walls and cooperating with said side and end walls to define openings of like peripheral configuration adjacent each end of said primary pan member, a second pan member of 4relative shallow dimension secured to said primary pan member and closing one of said openings and defining said scavenge sump, and a third pan `member secured to said primary pan member `and closing the other opening of said primary pan member, cooperating with said primary pan member to define said main sump said third pan member and being of a longitudinal dimension exceeding said other `opening whereby the bottom wall of said primary pan member defines an oil retaining baffle for said main sump, said second and third pan members being interchangeable to provide alternative main and scavenge sump locations of each end of said primary pan member.

14. In an internal combustion engine, an oil pan including a first pan member comprising side and end walls and a substantially flat bottom wall extending between said side walls and cooperating with said side and end walls to define openings of like peripheral configuration adjacent each end of said first pan member, a second pan member secured to said first pan member and closing one of said openings and cooperating with said primary pan member to define a main sump, and a third pan member secured to and closing the other of said openings and cooperating with said first pan member to define a scavenge sump.

15. An oil pan structure for an internal `combustion engine including a primary pan member comprising side and end walls and a bottom wall extending between said side walls and cooperating with said side and end walls to define openings of like peripheral configuration adjacent each end of said primary pan member, a second pan member of relative shallow dimension secured to said primary pan member and closing one of `said openings and defining a scavenge sump, and a third pan member secured to said primary pan member and closing the other opening of said primary pan member, said third pan member cooperating with said primary pan member to define a main sump and being of a longitudinal dimension extending beyond said other opening whereby the bottom wall of said primary pan member defines an oil retaining baffle for said main sump the mounting of said second and third pan members on said primary pan member being interchangeable to provide alternative main and scavenge sump locations for said engine.

16. In an internal combustion engine, a cylinder block having oil distribution passages therein, an oil pan secured to and defining a crankcase and oil sump chamber with said block, spaced bearing means carried by said block and rotatably supporting a crankshaft Within said crankcase chamber, a gear pump mechanism mounted within said crankcase chamber and including a housing defining a pumping chamber extending longitudinally in parallel relation to the crankshaft rotative axis, an inlet chamber opening to the lower portion of said pumping chamber land a discharge chamber opening on the upper portion of said pumping chamber, an intake means in said sump chamber having fiuid connection with said inlet chamber, a fluid connection between the discharge chamber and the oil distribution passages of said cylinder block, two irnpeller shafts journaled in and projecting from said housing in symmetrical parallel relation to the crankshaft rotative axis and a common tangent plane passing therebetween and through the crankshaft rotative axis, an impeller gear secured to each impeller shaft within said pumping chamber and having fiuid pumping interengagement with each other and 'rotative sealing clearance with the housing surfaces defining the pumping chamber, a gear member drivingly secured to said crankshaft and a driven gear secured to the projecting end of one of said impeller shafts and drivingly engaged by said crankshaft gear member to effect pumping displacement of fluid between the inlet and discharge chamber, said last mentioned gear including a spider portion having axial clearance with the other impeller shaft and being mountable on either impeller shaft to accommodate crankshaft trotation in either direction.

17. In the combination set forth in claim 16, said pumping chamber and impeller gears being of substantial longitudinal dimension relative to the pitch diameters of the impeller gears and the pumping chamber defining portions of said housing having a first plurality of arcuate surfaces defining spaced rotative clearances with the periphery of said impeller gears adjacent said inlet chamber thereby providing arcuate extensions of said inlet chamber, and a second plurality of arcuate surfaces of limited sector intersecting said first arcuate surfaces and having rotative sealing clearance with the peripheries of said impeller gears between said first arcuate surfaces and said discharge chamber.

References Cited in the file of this patent UNITED STATES PATENTS 1,667,728 Fisher May 1, 1928 2,147,405 Horton Feb. 14, 1939 2,177,724 Kishline Oct 31, 1939 2,424,750 Heckert July 29, 1947 2,572,250 Davis Oct. 23, 1951 2,728,413 Kremser Dee. 27, 1955 2,887,064 Say May 19, 1959 2,891,483 Murray et al. June 23, 1959 2,913,069 Kubis Nov. 17, 1959 2,955,675 Leach Oct. 11, 1960 2,965,036 Wood Dec. 20, 1960 FOREIGN PATENTS 125,797 Australia Oct. 14, 1947 

